Gas compressor



May 24, 1938. Q A BERGMANN 2,118,371

GAS COMPRESSOR Filed oct. 25, 1935 2 SheeS-Sheet l $6@ 1N BY ATTORNEY.

May 24, 1938-` c. A. BERGMANN 2,118,371

GAS COMPRESSOR Filed Oct. 25, 1935 2 Sheecses-SheecI 2 INVENTOR,

ATTORNEY'.

Patented May 24, 1938 PATENT OFFICE 2,118,371 GAS COMPRESSOR Carl A. Bergmann, Milwaukee, Wis., assigner to Walter D. Mann, Milwaukee, Wis.

Application October 25, 1935, Serial No. 46,807

19 Claims.

The present invention relates in general to improvements in gas compressors, and relates more specically to improved apparatus for compressing air or other elastic fluids with the aid of centrifugal force acting upon a carrier liquid.

Generally defined, an object of the invention is to provide improved apparatus for producing high compression of gases, in a substantially isothermal manner and with maximum efficiency.

While it has heretofore been proposed to utilize an ordinary centrifugal pump for the purpose of hydaulically compressing air to some extent, by mixing the air with the liquid passing through the pump rotor and by subsequently separating the air from the mixture expelled by the rotor, this method of compression is relatively ineicient and is not adapted for high compression of the gas.

In applicants prior Patent No. 2,025,037, a 2 compressor is shown and described, which is designed to effect any desired degree of compression of a gas with a minimum expenditure of power by utilizing centrifugal force to compress the `fluid while mixed with liquid, an-d by additionally utilizing the pressure acting upon the separated liquid to regain the energy which is substantially wasted when utilizing the ordinary centrifugal pump for air compression purposes. The compressor shown in said prior patent is further designed to produce substantially isothermic compression of a gas to relatively high pressures in a single stage; to minimize friction losses and leakage; and to produce entirely automatic and continuous operation wherein the iiuent compressing medium is repeatedly utilized and retained at a desired temperature.

The present invention is designed to retain all of the above-mentioned advantageous features and to provide certain improvements as follows:

To provide a compressor having a rotor wherein the cross sectional area of the ducts is smaller toward the outer rim to thereby maintain or increase the velocity and overcome the tendency of the air bubbles to slip, that'is, to travel backward.

To provide a device of the class described wherein the rotor ducts are so shaped as to prevent premature separation of the air from the water.

To provide a compressor wherein diffusion of the air and water takes place at the outer rim of the rotor.

To provide a compressor wherein the rotor ducts are pointed against the direction of rota- 55- tion of the rotor aty the discharge end of said ducts to thereby regulate the absolute discharge speed of the compressing fluid, as desired.

To provide a compressor wherein the rotor ducts are substantiallyfoval in shape to keep the hydraulic lossesV to a minimum.

To provide a compressor of the class described wherein the gas is mixed with the liquid in such a location and manner as to provide for elcient operation.

To provide a compressor which is self-priming, which nas novel means for effecting a seal between movable and stationary parts, and which has a bearing member and frictional sealing member which are automatically lubricated by the cooling liquid.

With the above and other objects in view, the invention consists of the improved gas compressor and all its parts and combinations as set forth in the claims, and all equivalents thereof.

In the accompanying drawings in which the same reference numerals designate the same parts in all of the views,

Fig. 1 is a transverse vertical sectional view of the compressor;

Fig. 2 is a fragmentary front end view of the rotor, parts being broken away and shown in section;

Fig. 3 is a similar View of the other end of the rotor, part of the stationary hub portion being shown in section;

Fig. 4 is a fragmentary sectional circumferential view of the rotor developed and taken on line l-li of Fig. 1;

' Fig. 5 is a longitudinal sectional view through the stationary compressor part;

Fig. 6 is a diagram of forces illustrating the section of a particle passing through a duct to show the action of a particle ofv liquid passing through the compressor duct;

Fig. 7 is a velocity diagram of the mixture entering the rotor intake ducts;

Fig. 8 is a velocity diagram of the returning liquid entering the ducts of the stationary compressor part;

Fig. 9 is a vertical sectional view through a modified form of compressor;

Fig. 10 is a fragmentary bottom view of the rotor of the modified form of compressor;

Fig. 11 is a circumferential section taken on line lI-H of Fig. 10 and developed;

Fig. 12 is an enlarged fragmentary sectional View showing the oat valve; and

Figs. 13-15 are side elevational views of a float in different positions to show the plane of operation.

Referring more particularly to the drawings, the numeral I2 designates a housing which may be suitably supported on legs I3. A shaft i4 is rotatably mounted in the housing and has one end journalled in a bearing I5. The shaft may be driven by any suitable means. Within the housing the shaft is formed'with an annular flange I6 to which a rotor I1 is secured by bolts or the like I 8. v

The majority of the inner portion of the rotor terminates short of the shaft I4 as at I9 and 26, and a stationary compressor part or duct forming' member 2I, which is complementary in shape to said inner portion of the rotor lls the space between the inner portions of the rotor and the shaft I4. The said stationary compressor part is provided with a tubular eXtension, the outer end of which is secured in an end opening of a cup shaped member 22, the said member 22 lbeing in turn fitted into a tubular boss 23 on the casing I2. An annular cover 24 has its outer periphery secured to the rotor I1 and has its inner periphery rotatably surrounding the tubular extension of the stationary compressor part 2 I. A carbon ring 25 secured to one end of a bellows 26 is urged into sealing relationship with the inner portion of the annular rotatable cover 24 by a coil spring 21.

A bearing housing 28 is fitted into the member 22 and is formed with an upwardly extending tubular member 29 forming an air inlet duct 3Q which communicates with an annular chamber 3|. The bearing housing 28 supports a bearing 32 within which the other end of the shaft I4 is journalled. A sealing ring 33 carried by one end of a bellows 34 is urged by a coil spring 35 into sealing relationship with the end of th-e shaft I4. The other end of the bellows is secured to a cap 36. It may readily be seen that air or other gas under pressure which is delivered by the compressor to the duct 31 of the shaft I4 can pass through the bellows 35, past a non-return check valve 38 in the cap 36, and into a pipe 39 leading to a reservoir 40.

A water cooler 4I is adapted to receive water through an inlet valve 42, until a discharge valve 43 overflows. The water from the cooler is adapted to pass through a pipe 44 into duct 45 of the stationary compressor part 2I and into A ducts 46 of said stationary compressor part.

v duits. When viewed from an end of the rotor, as

in Fig. 2, the portion of the duct 41 which leads to the duct 46 is curved as at 49, and the curve is formed by relatively small radii, and the adjoining portion of the duct 41 is of Voutwardly decreasing cross sectional area as shown in Figs. 1 and 2 and is formed by large radii to form an arc approaching a straight line, and said arc is angled away from the direction of rotation ofthe rotor as at 41 (Fig. 2). The outer portion of the duct 4 1 then curves abruptly to the periphery of the rotor, also preferably'in a direction opposed to the direction of rotation of the rotorfasrat I, and

Guide vanes 46, formed in the stationary compressor part 2 I, direct water admitted to the duct 46 with the absolute speed and direction C1 (see Fig. 7) past air intake slots 56 to the rotor entrance to give the water passing into the duct portions 49 the desired relative speed W1. It can be noted that the direction of the absolute speed C1 is pointed in the direction of the peripheral speed of the rotor U1 in order to reduce the absolute speed and losses of the water going through the duct portions 41.

In Fig. 6 (a) represents the eye of a rotor and (b) represents a curved duct. M represents a particle such as a particle of liquid in the present invention passing through said duct with a relative speed W1 (Fig. 7) while the duct rotates in the direction indicated by the arrow in Fig. 6.

Due to the peripheral speed U and radius (r) a centrifugal force (C) acts on the particle M in the radial direction indicated by the arrow at (C) to create one component C acting perpendicular to the wall and another component C'l acting tangentially to the walls. Due to the radius R and the relative speed W an additional centrifugal force ,D actingA in the direction of radius R is set up, and in addition there is an accelerating force E due to the angular speed of the duct and the relative speed W of the particle, which is set upacting in a direction opposite to C.V In accordance with the above, the shape of intake duct portions 49 and 4l!` of the rotor are so designed that the forces C', D and E' cancel each other, and only the force C" remains. This causes the particles to move through the ducts without being thrown against the walls and premature separation of the air or gas from the liquid is thus prevented. This makes efficient operation possible.

Due to the rotation of the rotor, water admitted to the duct 46 of the stationary compressor part is projected by centrifugal force through the duct portions 49, 41 and 5I. Air, which is sucked through an air cleaner 53, passes a nonreturn check valve 54, through duct 30, into the chamber SI, and through passage way 55 to air intake slots 56. Water passing into duct portions 41 produces a`Venturi effect and entrains air from the slots 56 which communicate with air passage ways 56', and the mixture of air and water passes through the compression duct portions 41, the air being in the form of small bubbles in the water and the columns of water being sub- 'ected to progressively increasing centrifugal force. Inasmuch as straight rotor ducts or ducts having ordinary or involute curves would tend to permit undesirable separation of the air bubbles from the water, resulting in an ineflicientrcompressor, the ducts in the present invention have been carefully planned as above described by reference to the diagram of Fig. 6 to prevent such premature separation.

Due to the curvature and flare of the ducts at 5I (see Fig. 2) the circulating speed of the mixture is reduced, which in turn causes higher pressure at the outer rim of the rotor and also assures complete separation of the air from the water at the proper time.

When the peripheral separating conduit 52 is reached', the air or gas under high pressure is expelled fromthe liquid by the continued action of centrifugal forces thereon to the inner portion 58 of the conduit 52, whereupon the float valves 59, which are pivoted as at B8, will ride in partially submerged condition upon the liquid level 6| to admit the compressed air to the ducts 62, the latter leading to the conduit 31 in the shaft |4 and ultimately to the reservoir 48 as above explained.

The float 58 is shown in detail in Fig. 12, and it may be seen that this float comprises a piece of relatively light material or metal 63 and a short length of heavier material or metal 84 secured vto one end thereof.. The entire iioat is fulcrumed as at 68 near one end of the light section of metal. The amount of both materials and the point of fulcruming are so worked out that the float balances on the fulcrum when it is approximately half submerged in the liquid which is used.

Figs. 13, 14, and 15 explain the' principle of this special float. Fig. 13 shows the float half. submerged in liquid, and it will be noticed that the float is balanced. Fig. 14 shows the float fully submerged in liquid, and it will be noted that due to the difference in specific gravity, the length of the lighter material B3 displaces more water than the length of the heavier material 64 so that the end 63 is lifted up by the liquid. Thus, with the float as applied to applicants apparatus, this movement would cause a closing movement of the valve to prevent escape of water. In Fig. 15 the action of this type of float, when entirely unsubmerged, is shown. Due to the greater weight and leverage of the lighter section 63, there would be a downward tilting of this end.

From the above it may be seen that the lighter portion E3 -may be half or partially counterbalanced by a heavier section 83, and the materials can thus be either lighter or heavier than the liquid employed. Ordinary floats must, of course, be lighter. With this float construction therefore, solid metal can be used which is necessary in the present use due to the tremendous pressures to which the material of. the float is subjected. Ordinary floats suciently small in size would fail to stand up under the pressure conditions. A spring 65 urges the valve to closing position when the compressor is idle to prevent liquid from entering the air discharge ducts.

The water in the peripheral conduit 52, from which the air has been separated, ows in the return duct portions 48 due to the lesser head of liquid in these duct portions which is sufficient to overcome the friction of the liquid iiowing through the rotor. The pressure and peripheral speed of the particles of the liquid are reduced while they return through conduits 48. The kinetic energy due to the peripheral speed of the liquid which is imparted to the particles of the liquid passing through the conduits-41 where they gradually reach the maximum peripheral speed in the conduits 52 is returned in conduits 48. The slower relative speed in the peripheral duct 52 is maintained through the ducts 48 to keep the hydraulic losses yas low as possible. The water is ultimately discharged into the ducts 46 for repetition of the cycle.

Referring to Fig. 8, the relative speed W2 is pointed away from the direction of the peripheral speed U2 as at 88 (Fig. 3) to obtain the desired absolute speed C2, so that the water enters the ducts at 63 with no pressure and with said speedl C2, which absolute speed is slightly higher than the absolute speed C1 to overcome the friction of the water passing through the ducts 46 and cause continued repetition of the cycle.

The operation of this form` of compressor is as follows: To start the compressor it is rotated in the direction indicated by arrows, and water is admitted to the cooler 4| through the intake valve 42 until the discharge valve 43 overcws, which valve is set at the same pressure as the static pressure in the duct 46 of the stationary compressor part. The water then flows through a pipe 44, duct 45 of the Stationary compressor part 2| into the ducts 46 and begins to circulate. The movement of the water in the ducts entrains air from the vane slots 58 as above explained in detail, and the separated compressed air is directed into the reservoir 48 as before explained, the water alone returning to the duct portions 48.

An annular space 61 within the rotor will be lled with water to the annular level 68. As soon as maximum air pressure is reached in the reservoir 48, .a piston controlled valve 69 is moved to the right, referring to Fig. 1, against the tension of. a spring 18 to bring a port 'll in the stem of the piston into registration with a duct l2 in the valve casing and thereby admit air from a pipe line 13 to a pipe line '|4, and the pipe line '|4 leads to the space in a cylinder 15 above a piston 16, which piston is mounted rigidly on a control tube ll. When the air enters the cylinder '|5, it will force the piston downwardly to move the control tube against the tension of the coil spring from the full line position of Fig. 1 to the dotted line position therein. This causes the open inner end of the control tube to be positioned in the duct 48. Water circulating rapidly through the duct 48 of the stationary rotor part will pass into the open end of the control tube, through said tube and into the annular space 81 of the rotor, and said water fills the annular space to the approximate water level 18.

As soon as enough air has been taken from the compressed air reservoir 48 to bring the pressure therein to a predetermined minimum, the spring 18 will move the control valve 89 back to the full line position of. Fig. 1 to thereby cause the port 1| in the piston stem to register with the duct 'i8 in the valve casing, and thus connect the pipe line 'i4 with the atmosphere. This naturally relieves the pressure on top of the control tube piston 'i8 and permits the tube to return to the full line position of Fig. 1. When in this position, the water in the annular space 67 of the rotor will enter the opening 88 in the upper end of the control tube and will be forced rapidly back into the ducts 46 and into the circuit for the compressor. The compressor will therefore again begin to compress air. When the compressor is idle, the water will drop to the lower portion of the compressor to the indicated level 8| This method of control is particularly adaptable for portable units which are driven by gas engines or the like, where the periods of rest are brief. For stationary work where electric motors are used and where the periods of rest are prolonged a suitable electric control may be employed.

During operation, part of the circulating water in the system continually passes out of opening 82 through duct 83 into pipe line 84 to the water cooler 4|. D'ue to the fact that the intake opening 82 for the cooling water is pointed against the direction of the circulating water, the kinetic energy of the water is transferred partially into pressure to eliminate the necessity of using a pump for driving the water through the cooler.

tube 44 and canal 45 into the circuit of the water.

Openings 35 in the compressor casing admit air from the eXterior, which air is blown out through other casing openings 96 to produce an additional cooling effect. The bearing 32 and the sealing ring 33 are of oilless construction being lubricated by the cooling water. The cooling water which is admitted at 88 cools the liquid passing through the cooler 4|. The reservoir 40 is also provided with a safety pressure relief valve 81.

The heat generated during the compression of the gas, is Vquickly absorbed by the carrier liquid thereby maintaining the compression substantially isothermic. Due to the absorption of the heat of compressionl of the liquid, this liquid upon entering the passages 40 will be heated, and in orderto maintain the carrier liquid. at substantially uniform temperature, a portion thereof is permitted to pass through the cooler 4|.

The annular separating conduit 52 communicates withv an annular compressed gas collecting duct 58 and the duct 52 insures a perfect balancing of the rotor. In case one compression conduit discharges more liquid than the other conduits, the annular level of the liquid is quickly equalized by the centrifugal force and the balance of the rotor is not destroyed.

The water which is condensed during operation of the compressor raises the static pressure within the stationary compressor part ducts and is discharged through discharge valve 43.

In Figs. 9 to l1, there is illustrated a modified form of compressor which differs from the compressor heretofore described principally in the mode of regaining the energy of the carrier liquid after the compressed gas has been liberated.

Referring rst to Fig. 9, it will be seen that there is a suitable base 90 which supports a lower stationary compressor part 9|. The center lower portion of said stationary compressor part supports a bearing- 92 through which a vertical shaft 93 is journalled, said shaft having an axial duct 94 thereinwhich communicates with its lower end. The-upper end of the shaft is journalled in a bearing 95 which is suitably supported by an upper casing part 06, said upper casing part being sup` ported on flanges 97v of the stationary compressor part. The shaft 93 may be suitably driven by a prime mover 98 of desired form.

Within the casing 96 and rigidly mounted on an upper portion of the shaft 93 for rotation therewith, is a rotor 99. It is to be noted that the rotor in this form of the invention cooperates with the stationary compressor part 9| to form ducts which are substantially oval in shape as shown in Fig. 9, said ducts being otherwise Very similar in construction to the compressor ducts in the form of the inventionA shown in Fig. l.

Referring to Fig. l0, it may be seen that the ducts are also designedto prevent premature separation of the gas from the liquid as heretofore described in detail in connection with the principal form of theV invention.

To start the compressor, it is rotated through operation of the motor 99, and water is forced through an intake valve |00 of a water controlling device |0|, The water flows through a pipe |02 into the ducts |03 of the stationary compressor part, and circulates through Vthe system until a discharge valve |011 overflows, said valve being set at the same pressure as the static pressure at the point |05 in the compressor when the compressor isV in operation.

'This water is cooled and returned through the The water circulates through the stationary ducts |03 of the compressor and through ducts |06 in the rotor. Guide vanes IH formed on an end of the stationary compressor duct |03, are formed in a similar manner to the guide vanes 46 shown in Fig. 6.Y Water circulating through the ducts |31in the direction indicated by the arrows in Fig. 9 passes these guide varies, and a Venturi action takes place to entrain air from slots in the guide vanes which slots are similar to the slots 56' shown in Fig. 6. The mixture of air and water then passes. through the duct portions |05` of the rotor in the manner heretofore described in detail in connection with the form of the invention shown in Fig. 1, and the mixture ultimately reaches the. annular separating chamber I2 where the compressed air is liberated from the liquid and collects in the annular'air space 3. Floaty valves H4, which are similar in action to the valves heretofore described in connection with Fig. l, control the passage of compressed air from the chamber ||3 through ducts H5 into the conduit 94 inthe shaft 93. The air then passes a non-return check Valve H5 into a pipe leading toV a compressed air reservoir similar to the reservoir of the principal form of the invention'` The Water which is separated from the air is forced through water discharge nozzles H8 with the relative speed' W, (see Fig. 11) which speed is nearly as great as the peripheral speed U of the nozzles I8, and the speedW is approximately opposedto the direction of the peripheral speed U, as shown in. Fig. 11. The water enters the ducts |03 of the stationary compressor part at ||9 with theV relative speed C and reenters the rotor ducts |06. with the slightly less speed due to the hydraulic losses in passing through the ducts |03. Y

The reaction of the jets of liquid delivered at high velocity from the nozzles IB during rotation of the rotor serves to simultaneously diifuse the pressure on the carrier liquid so as to augment the compression of the compressed gas and to assist in driving the rotor; thereby reducing the energy losses to a minimum. In this machine, as in the Vone previously described, the compression is eifected by centrifugalforceacting uponI liquid columns within the ducts |06 and the separation of the liquid and gas is likewise effected by centrifugal force within the rotor.

Air or gas is admitted through an air cleaner |20, tube I=2|, into space |22, within the casing. From said space, the ai-r enters through nonreturn check valves |23 into the annular air space |24 which in turn communicates with the slots in the Vanes wherethe air is introduced into the water circuit as heretofore described.

A part of the nozzles ||8 are supplied with float controlled needles |25 which are of well known construction and which are adapted to varyrthe cross sectional area of the nozzles and serve to prevent the air from blowing through the nozzles by maintaining the annular water level in the annular ducts ||3 at a level closer to the center of the rotor than the nozzle openings.

Cooling water may enter a pipe |26 in the water controlling Vdevice |0'|.f When the compressor is operating, pressure is built up within a space 271i within the sealing bellows |28 at the lower end of the shaft 931 Said pressure is transmitted through a tube |29 to ya chamber |30 in the water controlling device |0|. The said pressure in the chamber |30 acts on a bellows: [3| to open avvalve, |32 and admit the cooling water to the system through the pipe |02. This water forms part of the circulating water in the system and maintains the carrier liquid at a substantially uniform temperature. The water is ultimately discharged through Athe valve When the compressor is idle, the air pressure Within the spaces |21 and |36 disappears'and the valve |32 is closed so that no cooling water is consumed. When the compressor is idle, the water in the compressor flows to the lower por tion of the stationary compressor part and into the annular space |33 to approximately the level |34. When the compressor is started, the water within the annular space E33 flows through small openings |35 into annular space |33 and is raised by the centrifugal action within said space to the rotor ducts |06. The annular ledge i3? within the rotor space |33 prevents the water from getting to the outer portion of the rotor where it would cause too much friction. Y

During operation, additional water which is fed into the compressor, causes the average pressure of the circulating water to rise and when said pressure reaches a predetermined point, water is discharged through the discharge valve |04, which as before mentioned, opens at the same pressure as the desired static pressure at |05.

By referring to Fig. 10 it will be seen that the duct shapes shown in this figure are identical with the shapes of the ducts in the rst described form of compressor, except that the cross section of the ducts is not enlarged at the outer portion of the rotor. tion the water substantially maintains the speed on its way throughout the rotor until it passes the annular separating chamber H2, and it increases its velocity, due to the shape of the nozzles, to the speed W (see Fig. 11) when leaving the rotor, and little energy is left in the water which reenters the stationary ducts |03.

From the foregoing description it will be apparent that the invention provides a compact and eiiicient gas compressor wherein the actual compression and separation of the gases under pressure is effected with the aid of centrifugal force within a single rotor. The deceleration or diffusion of the carrier liquid is utilized in various ways to augment the gas compression, and the compressed gas is always delivered from the machine in relatively dry condition. It will also be seen that the compression is substantially isothermic. The heat resulting from the compression may be utilized for heating or other purposes thereby reducing the energy losses to a minimum.

It is apparent that the invention is adapted for many uses wherever the compression of gas is employed, such as in connection with refrigeration and gas turbines.

It should be understood that it is not desired to limit the invention to the exact details of construction and operation herein shown 4and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

What I claim is:- y

l. In a compressor, a rotor having therein a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas and liquid into the inner portions of each of said conduits, means communicating with said compression conduits for separating the compressed gas from the liquid, and means for independently conducting gas and liquid away from said separating means, said compression conduits However, in this form of the invenhaving their inner portions curved away from the direction of rotation of the rotor and then extending with less curve approaching a straight vline toward the periphery of the rotor to prevent premature separation of the gas from the liquid.

2. In a compressor, a rotor having therein a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas and liquid into the inner portions of each of said conduits, meanscommunicating with said compression conduits for separating the compressed gas from the liquid, and means for independently conducting gas and liquid away from said separating means, said compression conduits having their inner portions curved away from the direction of rotation of the rotor and then extending with less curve toward the periphery of the rotor and having their outer portions flared into communication with the separating means.

3. In a compressor, a rotor having therein a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas and' liquid into the inner portions of each of said conduits, means communicating with said compression conduits for separating the compressed gas from the liquid, and means for independently conducting gas and liquid away from said separating means, said compression conduits having their outer portions flared into communication with the separating means.

4. In a compressor, a rotor having vthereinv a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas and liquid into the inner portions of each of said conduits, means communicating with"said compression conduits forA separating the compressed gas from the liquid, and means for independently conducting gas and liquid away from said separating means, said compression conduits having their outer portions iiared and angled inwardly into communication with the separating means.

5. In a compressor, a central shaft, a fixed coml pressor part loosely surrounding said shaft and having a plurality of conduits therein, a rotor rotatable with the shaft around said fixed compressor part and havingcompression conduits communicating with one end of the conduits of the fixed compressor part and return conduits communicating with the other end of the conduits of the fixed compressor part, the ends of the conduits of the fixed compressor part which adjoin the compression conduits being separated by a plurality of vanes having axial slots, means for admitting gas to the slots of saidy vanes, and means for admitting liquid to the conduits of the fixed compressor part, said liquid being movable upon rotation of the rotor past said vanes and into the compression conduits to entrain gas from the slots in said vanes.

6. In a compressor, a central shaft, a xed compressor part loosely surrounding said shaft and having a plurality of conduits therein, a rotor rotatable with the shaft around said fixed compressor part and having compression conduits communicating with one end of the conduits of the iixed compressor part and return conduits communicating with the other end of the conduits of the fixed compressor part, the ends of the conduits of the xed compressor part which adjoin the compression conduits being separated by slotted vanes, means for admitting gas to the slots of said vanes, and means for admitting liquid to the conduits of the iixed compressor part, said liquid being movable upon rotation of the rotor past saidvanes and into the compression conduits to'entrain gas from the slots in said vanes, said vanesbeing pointed toward the direction of rotation of the rotor.

7. In a compressor having a rotor and having a plurality of compression conduits therein extending away from the rotor axis, means for delivering mixed gas and liquid into portions of said conduits, means for separating `the compressed gas from the liquid, 4a reservoir to which said compressed gas is conducted, means for returning the Yseparated liquid back to said compression conduits, and means responsive to a predetermined pressure in said reservoir for temporarily removing liquid from the circuit of said rotor conduits to render the compressor temporarily inactive.

8. In a compressor having a rotor and having a plurality oi' compression conduits therein extending away frorn the rotor axis, `means lfor delivering mixed gas and liquid into portions of said conduits, means for separating ,the compressed gas from the liquid, a reservoir to which said compressed gas is conducted, means for returning the separated liquid back to Vsaid -compression conduits,fand means responsive :to a predetermined pressure in said reservoir for temporarily removing liquid from the circuit of said rotor conduits to render -the compressor vtemporarily inactive, there being an annular chamber Within the rotor' for receiving said 'removed liquid. Y y v 9. In a compressor having a rotor and having a plurality of compression conduitstherein extending away from the rotor axis, means for delivering mixed gas andliquid into portions of said conduits, means for separating the compressed gas from the liquid, a reservo-ir towwhichV said compressed gas is conducted, means Vfor-returning the separated liquid back to said compression conduits, and means responsive to a pred'eter* mined pressure in said reservoir vfor temporarily removing liquid *from Vthe circuit V-o'f said lrotor conduits to render the compressor vtemporarily inactive, said means being' responsive to a drop in pressure in said reservoir ior returning the removed liquid tothe rotor conduit circuit.

10.` In a compressor having a'rotor andhaving a plurality of compression conduits Atherein extending away irom the rotorV axis, means for delivering mixed gas and liquid into portions of said conduits, means for'separating the comf pressed gas from the liquid, a reservoir to which said compressed gas is conducted, means for returning the separated liquid back to said compression conduits, and a by-passing tube inthe interior of the rotor movable in response toV a predetermined pressure in said reservoir to a position in the rotor conduits to intercept liquid therefrom and temporarily remove the same Vfrom the circuit.

11. In a compressor having a rotor and having a plurality of compression conduits therein extending -away from the rotor axis, vmeans for delivering mixed gas and liquid into portions of said con-duits, -means for separating the oompressed gas from the liquid, a reservoir to which said compressed `gas is conducted, fnieans for -returning the separated liquid back to said compression conduits, and a by-passing tubein the interior of the rotor movable is response to a predetermined pressure in said reservoir to a position in the rotor conduits to intercept liquid therefrom and temporarily remove theV same from Vthe circuit, said tube being movable in re- -sponse to a drop in pressure in said reservoir to return the removed liquid to the rotor conduit circuit.

l2. Ina compressor having a rotor, a shaftrfor said rotor having a duct therein, compression conduits in said rotor, means for delivering mixed gas and liquid to said compression conduits, means for separating compressed gas from the liquid, means for conducting said separated gas to the duct in the rotor shaft, and means for conductingthe compressed gas away from said duct in the rotor shaft including a bellows, a sealing ring on an end ofthe bellows, and yielding means for urging the ring into frictional engagement with a portion of the rotor shaft around the duct opening. Y Y

13. In a compressor having a rotor within which fluid is circulated, a lxed member about which said rotor revolves, and means for preventing loss of iluid from said rotor comprising a bellows surrounding said iixed member and having one end xed and closed, a sealing ring on the other end of said bellows, and yielding means for urging said sealing ring into frictional engagement with the rotor.

14. In a compressor having a rotor provided with ducts therein through which a compressing liquid is circulated by centrifugal force, a cooling unit, connections between said cooling unit and the rotor ducts, and means for utilizing the kinetic energy of the liquid to circulate said liquid through the cooling unit. Y

15. In a compressor, a rotor having therein a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas andV liquid into the inner portions of each of said conduits, means communicating with said compression conduits for separating the compressed gas from the liquid, means for conducting gas away from said separating means, return conduits for conducting the liquid from the separating means back to the compression conduit, nozzles for discharging the separated liquid from the separating means into the return conduits, and float controlled valves for regulating the liquid level adjacent the nozzles to prevent gas from escaping from said nozzles.

16. In a compressor, a rotor having therein a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas and liquid into the inner portionsY of each of said conduits, means communicating with said compression conduits for separating the compressed gas from the liquid, means for conducting gas and liquid away from said separating means, a cooler having a cooling chamber provided with a vent, means for leading liquid to said cooler and back again to the rotor, and a float valve control-ling said vent and operable when the liquid level in -the cooling chamber drops below a predetermined point to provide for escape of trapped air from the cooling chamber.

17. In a compressor, a vertically disposed rotatable shaft, a xed compressor part loosely surrounding said shaft and having Ya plurality of conduits therein, a rotor rotatable with the shaft above said iixed compressor part and having compression conduits communicable with the ends of the conduits of the fixed compressor part, means for delivering mixed gas and liquid into the inner end portions of each of said compression conduits, means for separating the compressed gas from the liquid, an annular chamber between the iixed compressor part and rotor into which liquid from the rotor ducts flows by gravity when the compressor is idle, and means between said chamber and the rotor constructed to provide for the utilization of centrifugal force to automatically return the water from said chamber to the rotor ducts when the compressor is started.

18. In a compressor, a vertically disposed rotatable shaft, a fixed compressor part loosely surrounding said shaft and having a plurality of conduits therein, a rotor rotatable with the shaft above said xed compressor part and having compression conduits communicable with the ends of the conduits of the xed compressor part, means for delivering mixed gas and liquid into f the inner end portions of each of said compression conduits, means for separating the compressed gas from the liquid, an annular chamber between the Xed compressor part and rotor into which liquid from the rotor ducts flows by gravity when the compressor is idle, means between said chamber and the rotor constructed to provide for the utilization of centrifugal force to automatically return the water from said chamber to the rotor ducts when the compressor is started, and an annular ledge Within said chamber for preventing said water in said chamber from traveling to the outer portion of the rotor.

19. In a compressor, a rotor having therein a plurality of compression conduits extending awayA from the rotor axis, means for delivering mixed gas and liquid into the inner portions of each of said conduits, means communicating with said compression conduits for separating the compressed gas from the liquid, means for conducting gas and liquid from said separating means, a source oi cooling water, and means providing for the automatic admission of cooling water to the compressor only when the compressor is operating.

CARL A. BERGMANN. 

